Fuel surcharge = (current diesel price − base peg) ÷ divisor MPG.
The EIA national diesel average for the week of September 21, 2026 was
$6.529, up $0.244 on the
week and $2.780 on the year. On an example
$1.20-peg, 6.0-MPG schedule that is 88.8¢ per loaded mile. Check your own
schedule below, and see whether it actually makes your truck whole.
Fuel Surcharge Calculator
Check a DOE-pegged fuel surcharge the way the contract computes it: current diesel price minus the base peg, divided by the schedule's MPG. Then compare what it pays against what the price rise really costs your truck.
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Thinking about factoring your loads?
The surcharge recovers fuel money on the invoice's timeline, but the pump charged you today, and a schedule that under-recovers at your real MPG widens that gap every mile. Factoring advances the invoice so the recovery lands closer to the fill-up.
The formula is simple; the assumptions are where the money moves
A DOE-peg surcharge schedule makes three choices, and each one shifts money
between you and the shipper. The index decides which diesel
price counts, usually the EIA's weekly national average, sometimes a
regional one. The peg decides where the surcharge starts
paying: everything below the peg is your problem, priced into the linehaul.
The divisor decides how many miles the schedule thinks a
gallon covers, and every tenth of MPG your truck falls short of it is a
cost increase you eat.
That third one is the quiet one. A 6.0 divisor against a truck really
running 5.0 MPG leaves about 18 cents a mile unrecovered at the
price above: about $89 on a single 500-mile run, all of it invisible if
you only ever look at the surcharge line and never at your own burn.
Where diesel sat in the week of September 21, 2026
Figures are the EIA on-highway averages for the week of September 21, 2026,
taxes included. The spread matters: a nationally pegged schedule pays the
same surcharge in Georgia and in California, while the pump does not.
Region
$/gallon
U.S. national average
$6.529
East Coast (PADD 1)
$6.268
New England
$6.517
Central Atlantic
$6.546
Lower Atlantic
$6.139
Midwest (PADD 2)
$6.680
Gulf Coast (PADD 3)
$6.177
Rocky Mountain (PADD 4)
$6.340
West Coast (PADD 5)
$7.456
West Coast less California
$6.791
California
$8.246
Source: U.S. EIA On-Highway Diesel Fuel Prices (weekly national average),
updated weekly, usually on Tuesday. The calculator's default price is this number; if your
schedule names a regional index or your contract updates on a different day,
type that price in instead.
What this calculator does not model
Many published schedules are stepped tables (the surcharge moves in
five-cent price bands, rounded to the cent), so your contract's table
may sit a fraction above or below the continuous formula shown here. Some
pay on all dispatched miles rather than loaded miles only. And none of this
touches what the fuel actually costs you on a specific run: for that, put
your real miles, MPG, and pump price into the
truck fuel cost calculator.
Worked examples
EIA diesel for the week of 2026-09-21 ($6.529), $1.20 peg, 6.0 divisor, 500 loaded miles, truck runs 6.5 MPGThe schedule pays $0.888 per mile ($444.08 across the loaded miles). At your real MPG the price rise costs $0.820 per mile, so the schedule covers it with $0.068 per mile to spare.
Same week on a $2.50-peg / 5.5-divisor schedule, per-mile figure onlyThe schedule pays $0.733 per mile.
A thirsty truck: 5.0 real MPG against the 6.0 divisor eats the gapThe schedule pays $0.888 per mile ($444.08 across the loaded miles). At your real MPG the price rise costs $1.066 per mile, so the schedule leaves you eating $0.178 per mile.
Fuel surcharge questions, answered
How is a fuel surcharge calculated?
Most trucking contracts use the DOE-peg formula: take the current national average diesel price, subtract the contract's base (peg) price, and divide by an agreed miles-per-gallon figure. The result is the surcharge per mile. At the national average of $6.529 for the week of September 21, 2026, with a $1.20 peg and a 6.0 divisor, that is about 88.8 cents per loaded mile. Every number in that sentence is negotiable except the diesel price, which is why the peg and the divisor in your contract matter as much as the rate.
What diesel price do surcharge schedules use?
Almost always the U.S. Energy Information Administration's weekly on-highway diesel national average, published weekly, usually on Tuesday morning (Eastern time). Some schedules use one of EIA's regional averages instead: a PADD region, or a separate series such as California, which EIA publishes on its own inside the West Coast region. That matters: for the week of September 21, 2026 the national figure is $6.529 while California sits at $8.246; a schedule pegged to the national number under-recovers a West Coast operation by design. Check which index your contract names.
What base price and divisor are typical?
It varies by contract: the peg and the divisor are whatever your contract says. A lower peg starts paying sooner; a higher divisor pays less per mile at the same diesel price, so a schedule with a generous-looking rate and a high divisor can pay less than a modest rate over a low one. The $1.20 peg and 6.0 divisor used on this page are examples to make the arithmetic concrete, not a market benchmark. Put the numbers from your own contract into the calculator before signing anything.
Does the fuel surcharge actually cover my fuel cost?
Only if your truck matches the schedule's assumptions. The surcharge assumes the divisor MPG; your truck burns at its real MPG. If the schedule divides by 6.0 and you run 6.5, you pocket the difference. If you run 5.0 (winter, mountains, heavy loads), the same schedule quietly leaves you paying part of the increase yourself. That gap is the number this calculator puts in front of you, and at the diesel price shown on this page a truck running 5.0 MPG against a 6.0 divisor gives up about 18 cents a mile.
Is a fuel surcharge required by law?
No. There is no federal mandate that shippers or brokers pay a fuel surcharge, and no law that says how one must be computed. It is purely contractual, which is exactly why the formula deserves scrutiny before you sign. If a rate confirmation is silent on fuel, the linehaul rate is carrying all of the price risk: in the EIA week of September 21, 2026 diesel was $2.78 a gallon higher than a year earlier.
Does the surcharge apply to empty miles?
Usually not: most schedules pay on loaded miles only, which means the diesel you burn on deadhead comes out of your pocket at full price. If a quarter of your miles are empty, your effective recovery per gallon is a quarter lower than the schedule suggests. Some contracts do pay on all dispatched miles; it is worth asking for, especially when prices are climbing.
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Last reviewed by
Crossroads Technologies, published on Big Rig Math. The formula is written out on this page, and each worked example is produced by the same code that runs the calculator and is checked by automated tests every time the site is built. The default diesel price is the EIA weekly figure for the week shown on the page.
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